A group of robbers is commonly called a Band. Other collective nouns you may see include Gang and Crew.
A cast of robbers is a collective noun used to refer to a group of individuals who engage in criminal activities by stealing or unlawfully gaining possession of another person's property. Similar to a gang, this collective noun describes a group of thieves or burglars who collaborate, often sharing strategy, tools, and resources as they plan and execute their illicit endeavors. A cast portrays a sense of coordination and roles within the group, emphasizing the collaborative nature of their criminal activities. This collective noun suggests a common purpose, camaraderie, and possibly even a hierarchy among the members who constitute the cast of robbers.
Known collective nouns for Robbers include: